<!DOCTYPE HTML>
<html>
<head>
  <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
  <title>热身</title>
</head>
<body>
<p id="p1">我是第一段文字</p>
<p id="p2">我是第二段文字</p>

<script type="text/javascript">
  document.write("hello");
  document.getElementById("p1").style.color = "blue";
</script>
</body>
</html>